Corey McGee

First dorsal interosseous muscle contraction results in radiographic reduction of healthy thumb carpometacarpal joint

INTRODUCTION Hand therapists selectively strengthen the first dorsal interosseus (FDI) to stabilize arthritic joints yet the role of the FDI has not yet been radiographically validated. PURPOSE To determine if FDI contraction reduces radial subluxation (RS) of the thumb metacarpal (MC). METHODS Fluoroscopy was used to obtain true anterior-posterior radiographs of non-arthritic CMC joints: 1) at rest, 2) while stressed and 3) while stressed with maximal FDI contraction. Maximal FDI strength during CMC stress and thumb MC RS and trapezial articular width were measured. The ratio of RS to the articular width was calculated. RESULTS Seventeen participants (5 male, 12 female) participated. Subluxation of a stressed CMC significantly reduced and the subluxation to articular width ratio significantly improved after FDI activation. CONCLUSIONS Contraction of the FDI appears to radiographically reduce subluxation of the healthy thumb CMC joint. Further exploration on the FDIs reducibility and its carry-over effects in arthritic thumbs is needed. LEVEL OF EVIDENCE 4.

Measuring intrinsic hand strength in healthy adults: The accuracy intrarater and inter-rater reliability of the Rotterdam Intrinsic Hand Myometer

Study Design: Clinical measurement study. Introduction: Measuring the isometric strength generated during isolated hand joint motions is a challenging feat. The Rotterdam Intrinsic Hand Myometer (RIHM; med.engineers, Rotterdam, Netherlands) permits measurement of isolated movements of the hand. To date, there is limited evidence on the inter‐rater reliability and limited adult normative data of RIHM. Given that multiple raters, often with varying degrees of experience, are needed to collect normative data, inter‐rater reliability testing and a comparison of novice and experienced raters are needed. Purposes of the Study: The purposes of this study were to test the accuracy, intrarater reliability, and inter‐rater reliability of the RIHM in healthy‐handed adults. Methods: RIHM accuracy was tested through use of precision class F weights. Adults 18 years or older without upper limb dysfunction were recruited. Each participant was tested by 4 raters, 3 occupational therapy graduate students, and an experienced certified hand therapist, through use of a calibrated RIHM. Five strength measures were tested bilaterally (ie, thumb carpometacarpal palmar abduction, index finger metacarpophalangeal [MP] abduction, index finger MP flexion, thumb MP flexion, and small finger MP abduction) 3 times per a standardized protocol. Statistical methods were used to test accuracy, inter‐rater reliability, and intrarater/response stability. Results: The accuracy of RIHM device error was 5% or less. Reliability testing included the participation of 19 women and 10 men (n = 29). All raters were in excellent agreement across all muscles (intraclass correlation coefficient, ≥0.81). Low standard error of measurement values of ≤8.3 N (1.9 lb) across raters were found. The response stability and/or intrarater reliability of the novice and certified hand therapist raters were not statistically different. Discussion: The RIHM has an acceptable instrument error; the RIHM and its standardized procedure have excellent inter‐rater reliability and response stability when testing those without hand limitations; and the response stability and/or intrarater reliability of expert and novice raters were consistent. Conclusions: The use of the RIHM is justified when multiple raters of varying expertise collect normative data or conduct cohort studies on persons with healthy hands. Future research is warranted. Level of Evidence: Not applicable.

Evaluation of Hand Forces During a Joint-Protection Strategy for Women With Hand Osteoarthritis

OBJECTIVE. We evaluated whether a joint-protection strategy changes the mechanics of opening a sealed jar. METHOD. Thirty-one adult women with hand osteoarthritis attempted to open a “sealed” jar instrument when using and not using nonskid material. Grip force, torque, success, and pain were recorded for each trial. RESULTS. Participants used less grip force when twisting with their left hand. The greatest torque and success, yet the least amount of grip force across time, and pain was noted when the left hand turned the lid, the jar was held vertically, the right hand supported the base, and nonskid material was used. CONCLUSION. Women with hand osteoarthritis should be educated to consider the hand they use and their approach when opening sealed jars. Use of nonskid material without additional reasoning may increase load on arthritic joints, pain, and dysfunction. Additional research on task kinematics and the kinetics of the stabilizing hand is needed.

Development, construct validity, and reproducibility of a mimetic sealed jar measuring the dynamics of opening

Measurement of the dynamic kinetics involved in opening a jar may enable health care professionals to understand and train individuals in optimal hand/grip mechanics. This technical note details the design, validity, and reproducibility testing of a mimetic jar capable of measuring the forces and moments and isolated digital forces applied to the lid of the jar. An ecological jar instrument was designed with a torque limiter to provide a natural opening mechanism while a six-axis load cell and force sensing resistors recorded the way individuals applied force to the jar and lid during opening of a sealed container. A total of 115 volunteers participated in a validation of the device and an additional 36 participated in repeatability testing. Compared with prior instruments, this mimetic jar provides more force data and a simulated opening experience – making this jar instrument unique. Future studies utilizing the jar designed herein may allow health care professionals to evaluate patients suffering from debilitating osteoarthritis, fibromyalgia or other neuromuscular conditions and offer improvement strategies.

Reference values of intrinsic muscle strength of the hand of adolescents and young adults

Study Design: A cross‐sectional clinical measurement study. Introduction: Measuring intrinsic hand muscle strength helps evaluate hand function or therapeutic outcomes. However, there are no established normative values in adolescents and young adults between 13 and 20 years of age. Purpose of the Study: To measure hand intrinsic muscle strength and identify associated factors that may influence such in adolescents and young adults through use of the Rotterdam intrinsic hand myometer. Methods: A total of 131 participants (male: 63; female: 68) between 13 and 20 years of age completed the strength measurements of abductor pollicis brevis, first dorsal interosseus (FDI), deep head of FDI and lumbrical of second digit, flexor pollicis brevis (FPB), and abductor digiti minimi. Two trials of the measurements of each muscle were averaged for analyses. Self‐reported demographic data were used to examine the influences of age, sex, and body mass index (BMI) on intrinsic hand muscle strength. Results: Normative values of intrinsic hand muscle strength were presented by age groups (13, 14, 15‐16, 17‐18, 19‐20 year olds) for each sex category (male, female). A main effect of sex, but not age, on all the muscles on both the dominant (FPB: P = .02, others: P < .001) and non‐dominant (FDI: P = .005, FPB: P = .01, others: P < .001) sides was found. A significant effect of BMI was found on dominant (P = .009) and non‐dominant abductor pollicis brevis (P = .002). In addition, FDI (P = .005) and FPB (P = .002) were stronger on the dominant side than the non‐dominant side. Discussion: Intrinsic hand muscle strength may be influenced by different factors including sex, BMI, and hand dominance. A larger sample is needed to rigorously investigate the influence of age on intrinsic strength in male and female adolescents and young adults. Conclusion: The results provide reference values and suggest factors to be considered when evaluating hand function and therapeutic outcomes in both clinical and research settings. Further study is recommended. Level of Evidence: VI.

Inter-rater and inter-instrument reliability of goniometric thumb active and passive flexion range of motion measurements in healthy hands:

Introduction Goniometry is a common measure of range of motion and may be assessed by different therapists and goniometers. To date, there is limited psychometric data on active and passive range of motion measurements of individual thumb joints. The purpose of this study was to analyze inter-rater and inter-instrument reliability of passive and active flexion goniometric measures of thumb joints in healthy adults. Methods A within-subjects psychometric design was utilized. Two raters each used two goniometers (Baseline™ Flexion-Hyper Extension and Baseline™ 180 Degree Digit) to measure each participant’s (n = 48) thumb carpometacarpal, metacarpophalangeal, and interphalangeal flexion range of motion. Inter-rater and inter-instrument reliability and stability were evaluated through use of intraclass correlation coefficient, standard error of the measurement, and minimal detectable change test statistics. Results Inter-rater reliability was poor for carpometacarpal flexion and good-to-excellent for metacarpophalangeal and IP flexion. Between-rater error ranged between 3.9 and 6.3 degrees for active measurements and between 3.9 and 7.9 degrees for passive. Error was generally less when using the Baseline™ 180 Degree Digit goniometer. Inter-instrument reliability was excellent for all joints. Discussion These findings validate the concerns that thumb goniometry inter-rater reliability may differ in clinical and non-clinical populations, support further study in clinical populations, and support a common assumption that the same rater should test the same client with the same goniometer to minimize measurement error. When compared to the Baseline™ Flexion-Hyper Extension Goniometer, the Baseline™ 180 Degree Digit had higher repeatability across raters. Further research on within-rater reliability is required as is study on clinical populations.

Building student community in a hybrid program.

ABSTRACT The concept of student community has been shown to enhance learning, empower students, and increase engagement in the learning process. An occupational therapy program transformed classroom-based learning to a hybrid platform with over 70% of the course content online and expanded from one to two learning sites. Based on faculty concerns about occupational therapy students’ experience of belonging to a community, this study compared student-perceived sense of community in the first and final didactic semesters of a hybrid Masters program. Using the Classroom and School Community Inventory and a Checklist of 24 Points of Contact, faculty found over 90% of students reported a sense of community with no significant differences from start to finish of the didactic program, or between learning sites. Furthermore, students reported informal, out-of-classroom interactions with colleagues, group assignments, and face-to-face classroom sessions as the strongest points of contact contributing to a sense of student community.

Mimetic Jar Device Capable of Measuring Dynamic Opening Forces: Development and Validation

INTRODUCTION On a daily basis, individuals open household jars without considering the biomechanical requirements involved, but for some people this task can be difficult to complete. Those with osteoarthritis, fibromyalgia or other neuromuscular conditions need to make accommodations to their hand kinetics to successfully open a jar with minimal pain. Unfortunately, there exists little data to help clinicians suggest proper hand kinetics for these individuals. Many jar instruments have been developed to attempt to address these large populations; however, none of these jar instruments include a combination of : a six-axis load cell capable of measuring the total compensatory forces applied to the jar lid, multiple lid grip sensors, and a torque limiter to repeatedly simulate the experience of opening a sealed jar . Similarly, those who have quantified the forces and moments acting upon a jar have created instruments that are not true to form and presumably alter the natural requirements of the task. Thus, we developed a life-like device to measure the full kinetics of the hand during jar opening, including both grip forces and resultant forces applied to the jar in six degrees of freedom. This instrument was validated by bench top and healthy human subject testing. Subsequent testing with this jar device may help clinicians advise suitable hand kinetics for individuals with neuromuscular conditions to maximize their effective forces on the jar and minimize pain during jar opening. METHODS A jar device was designed and constructed so as to measure the 6-axes of forces and moments applied to the jar between the two hands as well as the grip forces on the lid (Fig. 1). This jar device utilized a torque limiter set to 2.4 Nm and the jar lid would open freely for 45o to provide a similar experience to opening a real jar. The lid was equipped with 5 mm force sensing resistors (FSR) to measure the force magnitude and direction of force application while gripping the lid (Fig. 1B). The instrumentation of the jar was designed to work with two interchangeable lids: 83 mm (Fig. 1A) and 55 mm (Fig. 1C). Each of these jars utilizes the same load cell and torque limiter and a size appropriate instrumented lid with identical force sensing transducers. The large jar is outfitted with 6 sensors equally spaced radially around the lid, while the small jar has 4.